French nutritionist Pierre Dukan, whose protein-rich diets are popular from Hollywood to Paris, lost in court Tuesday against a rival he accused of libel _ and was fined himself.
Dukan had filed a legal complaint against another diet doctor, Jean-Michel Cohen, who criticized Dukan's method in a magazine.
A Paris court ruled Tuesday that there was nothing libelous about Cohen's comments, and ordered Dukan to pay euro3,000 ($4,300) in damages for "abusive procedure."
Cohen said in a June 2010 magazine article that among some patients, the Dukan method could create "serious health problems such as high cholesterol, cardiovascular ailments and breast cancer."
Dukan issued a statement Tuesday defending the safety of his diet, saying he has 24 million followers and that Cohen "appears to have taken umbrage at the wave of enthusiasm for the Dukan phenomenon."
Dukan's book was France's best-selling publication last year and is on multiple U.S. best-seller lists, counting Hollywood and music stars among its devotees.
"It is not because you are a good businessman, a good communicator often on the covers of magazines that you can escape from a legitimate scientifically based critique," said Cohen's lawyer Richard Malka outside court. "What is essential is the safety of the patients and not the touchiness of the doctors."